1. Field of the Invention
The present invention relates to a creel mechanism of a ring spinning frame provided with conventional mechanism except the creel mechanism, more particularly an improvement of the creel mechanism of the conventional ring spinning frame.
2. Description of the Related Art
Japanese Unexamined Patent Publication Sho 64 (1989)-52828 discloses a unique creel mechanism applied to a conventional ring spinning frame provided with a plurality of draft parts arranged at each side thereof, wherein two alignments of bobbin hangers are arranged along the longitudinal direction of said ring spinning frame, a plurality of roving guides, each provided with two hook-shaped guide elements, are arranged in an alignment at an intermediate position between said two alignments of said bobbin hangers, in parallel thereto, so that rovings from roving bobbins supported by corresponding pair of said bobbin hangers, one of which is a bobbin hanger of a backside alignment of said two alignments of bobbin hangers and the other is a corresponding bobbin hanger of a front side alignment of said two alignments of bobbin hangers, facing the above-mentioned front bobbin hanger, and each roving guide member is connected to a solid portion of the creel mechanism by way of a flexible element such as a spring. Accordingly, each roving guide member can be displaced from the standby position coinciding to the above-mentioned intermediate position by coming into contact with a full packaged bobbin, which is being displaced to the corresponding back bobbin hanger, without applying a positive bending force, and of returning from the displaced position to the standby position after the above-mentioned insertion of the full packaged roving bobbin.
Japanese Examined Patent Publication Hei 2 (1990)-38500 discloses another type of creel mechanism of the conventional ring spinning frame wherein two alignments of bobbin hangers arranged in the same condition as the first mentioned prior art and a plurality of flat roving guide members, each provided with a pair of hooked shaped guide elements, arranged at an intermediate position between the above-mentioned two alignments of bobbin hangers, and said two roving guide elements of each roving guide member are arranged along a direction perpendicular to the lengthwise direction of the ring spinning frame.
In the first mentioned prior art, however, since the two roving guide elements of each roving guide member are parallel to the alignments of the bobbin hangers, at the time of each unit operation of the roving bobbin exchange operation, wherein two almost exhausted roving bobbins supported by two adjacent bobbin hangers of the backside alignment of the bobbin hangers are simultaneously exchanged with full packaged roving bobbins, respectively, when the full packaged roving bobbins are to be simultaneously exchanged with the corresponding almost exhausted roving bobbins supported by the two adjacent bobbin hangers of the backside alignment, each of the full packaged roving bobbins must pass through a space between two adjacent roving guides. This space, however, is not sufficient to allow a free passage therethrough of a full packaged roving bobbin, and thus the outside surface of the full packaged roving bobbin is forced into contact with the roving guide members and pushes the roving guides against the resilient force of the spring element of the roving guide, and accordingly, the possibility of an abrasion of the outside roving layer of the full packaged roving bobbin by the roving guide members is created, and the outside roving layer of the full packaged roving bobbin may be damaged In addition to the above-mentioned problem, it is also necessary to cover the spring elements with a cover piece, to prevent a possible deposition of free fibers on the spring elements
The second mentioned prior art has the following problem, i.e., since the intervening distance between two adjacent roving guide members is double the spindle pitch, the diameter of the full packaged roving bobbin is slightly smaller than the above-mentioned intervened space, e.g., 7 mm in a normal condition of the spinning operation. Therefore, to ensure a free passage of the full packaged roving bobbin through the above-mentioned space when carrying out the roving bobbin exchange operation, it is necessary to use a flat shaped roving guide member having a precise thickness and the roving guide members must be carefully arranged to maintain a uniform intervening space, to thereby guarantee the free passage of the full packaged roving bobbins between the respective two adjacent roving guide members. In our experience, however, it is evident that the preparation of such roving guide members having a precise uniform thickness, and the above-mentioned precise arrangement of the roving guide members, is very difficult, and therefore, it is apparent that the second mentioned prior art is not practical.